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Reference to IPACS Computer Code:
Chamis, C.C. and Shiao, M.C., IPACS —Integrated Probabilistic Assessment of Composite Structures: Code Development and Applications. Third NASA Advanced Composite Technology Conference, Vol. 1, Pt. 2, NASA CP–3178–VOL–1 –PT–2, 1993, pp. 987–999.
This slide is FROM:
Cristos C. Chamis (NASA Glenn Research Center, Cleveland, Ohio 44135, USA), “Dynamic probabilistic instability of composite structures”, publisher and date not given in the pdf file; most recent reference is 2001.
ABSTRACT: A computationally effective method is described to evaluate the non-deterministic dynamic instability (probabilistic dynamic buckling) of thin composite shells. The method is a judicious combination of available computer codes for finite element, composite mechanics and probabilistic structural analysis. The solution method is incrementally updated Lagrangian. It is illustrated by applying it to thin composite cylindrical shell subjected to dynamic loads. Both deterministic and probabilistic buckling loads are evaluated to demonstrate the effectiveness of the method. A universal plot is obtained for the specific shell that can be used to approximate buckling loads for different load rates and different probability levels. Results from this plot show that the faster the rate, the higher the buckling load and the shorter the time. The lower the probability, the lower is the buckling load for a specific time. Probabilistic sensitivity results show that the ply thickness, the fiber volume ratio and the fiber longitudinal modulus, dynamic load and loading rate are the dominant uncertainties in that order.
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